If you have been literally “caught napping” on your desk in the past and have been called lazy for that, you need not feel guilty anymore. But now there is scientific evidence that napping has positive effects on your overall health. There are numerous studies available now that claim that napping enhances productivity, mood, alertness and cognitive performance. But yes, it depends on how long should you nap.
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The studies say that the perks of a short nap that is less than 20 minutes (anywhere between 5-15 minutes) are almost immediate and last from anywhere between 1-3 hours. But if you exceed the 20-minute mark, (which is not very surprising because once you have gotten a taste of the delicious drowsiness, you don’t want to let go of it) it may cause sluggishness (for a brief period) but could enhance the cognitive performance for longer.
Speaking of exceeding the 20-minute mark, the National Aeronautics and Space Administration (NASA), revealed in a study on pilots that a 26-minute nap (in flight, while the plane was being co-piloted) improved vigilance by 54% and improves efficiency by 34%. One of the other factors that would influence the benefits of this mid-noon nap is the circadian timing or rhythm.
What Is the Circadian Timing?
We have referred to it as the “body clock” so many times that we never bother finding out what it exactly means. The circadian rhythm is this exact body clock or 24-hour cycle that tells the body when to sleep or eat and is determined by environmental factors such as daylight and temperature. These rhythms or timings also determine whether the body should feel wakeful or groggy depending on what time it is. If they are disturbed or hampered, they, in turn, affect the eating and sleeping patterns.
Most people sleep at night as dictated by their circadian rhythms, but there are many of us who like a nap in the afternoon or during weekends. There are some employers such as Nike or Google who encourage napping as a part of the office culture, while school children in Taiwan and China are also encouraged to take an hour’s nap after lunch.
There are two phases of the circadian timing, the non-REM sleep or the quiet sleep, and dreaming sleep or the REM sleep. Let’s take a look at both:
Non-REM Sleep
This sleep has three stages (the third stage being the deepest), all of which are characterized by how much they are disconnected from their sensory and motor functions when it comes to the surrounding environment. Let’s take a quick look at these stages:
Stage N1
This is the stage between wakefulness and sleep, the eyes are still active and may open and close every now and then. The heart rate begins to slow down and the breathing becomes more regular and sudden twitches are common. This is an easily-disturbed, very light sleep and the person would be aware of the sounds around them. The person will disregard that they had ever gone to sleep at all if woken up during this stage. Of the total sleep time, this represents only 5%.
Stage N2
In this stage, the conscious awareness levels start decreasing rapidly and the muscle activity slows down considerably. The sleeper is not aware of any sounds being made around them at this time. This stage is long, and the sleeper can spend as much as half the night in this stage. As the body temperature drops, it is getting ready for deep sleep.
Stage N3
Otherwise called the delta sleep, in this stage of deep sleep, the body is even less responsive to sounds from the outside environment and unaware of any stimuli and the outside world. The breathing becomes more regular, the pulse falls as much as 30% below the normal rate and the blood pressure falls. This stage was earlier divided into two stages (there would be an N4), depending on the delta wave frequencies.
REM Sleep
Sometimes called “stage 5” of the sleep cycle, the rapid eye movement (REM) sleep stage is different from all other stages because the brain is very active during this stage. Infants spend about 50% of their total sleep time in this stage, while adults spend almost 20%. The brain is, in a way of saying, on fire, thinking and dreaming, and the eyes dart back and forth behind the closed lids. The rest of the body remains immobile as the mind goes into an overdrive. The blood pressure goes up and the breathing and heart rates go back to the daytime levels. At the end of this sleep cycle, individuals start waking up gradually, and the body temperature goes up to prepare it for the day ahead.
Now that we have taken a look at the sleep cycles, it is clear that the way to ensure a refreshing nap is to wake up during the non-REM stages of sleep and the best amount of time to nap is the time while you are experiencing the N1 sleep. If you go any deeper into the N2 sleep stage, you will wake up groggy and disoriented and stay in that state for a long time.
How Long Should a Power Nap Be
Napping is a common enough practice seen in babies and younger children, but there are millions of people who retain this particular habit throughout their lifespan and Isaac Newton, Winston Churchill, Leonardo da Vinci and Albert Einstein are some of these people. But is there something called the best nap length? Apparently, there is.
As we mentioned earlier, short, 10-15 minute naps indicate a sharp improvement in cognitive performance. Sleepers after a nap of this duration were found to be more aware and active and the effects lasted for more than 1.5 hours.
There have been a number of studies to determine the length of the shortest possible nap that can be taken to attain the best results. Simultaneously, more studies were conducted to determine the longest stretch of nap that could be taken without the effects of sleep inertia.
These studies were conducted on people who normally never took a nap and those who took naps of 5-30 minutes. The ones who woke up after the 5-minute duration reported that there was not much improvement after that period. But other who took a half-hour nap reported that after the initial disorientation they experienced improvement in cognitive performance that lasted about 1.5 hours, which was similar to people who napped for 10-15 minutes.
From the studies, it was fairly conclusive the benefits of a 10-15 minute nap could be seen almost immediately, whereas longer naps needed the inertia to dissipate before the effects could be seen.
Other Factors to Consider
The time of the day is a very important factor when we are talking about nap times. Human bodies prefer to go to sleep twice during the day; during early mornings between 2-4 am, and in the noon, at around 1-3 pm. If you have ever wondered why you get drowsy in the afternoon, it is certainly not because of a heavy lunch or the weather, it is your brain releasing a sleep-inducing hormone called melatonin. Experts say that it is all right to give in to these naps in the noon, as long as they do not exceed more than 20 minutes, otherwise, it may interfere with your memory, mood, coordination and alertness.
Schedule your sleep
It would help you if you can set your sleeping patterns for the day. Avoid a nap at least three hours before you go to sleep because it would disrupt your sleep cycle. If you are one of those people who is an early riser, say at around 6 am, you might feel the need to nap at around 1-1:30 pm. Similarly, if you are a night owl, try going to bed late, say by around 1 am, so that your body gets the sleep it needs and you wake up refreshed and energized.
Enhance Your Napping Experience
Let us briefly take a look at how you can enhance your naps. These methods are very practical and you should have no problems following them:
- Cut down on Screen Time: If deep sleep is eluding you, it is essential that you switch off your electronics before you nap. It may be difficult in the beginning, but with determination, you can overcome this impediment.
- Check Your Room Temperature: The temperature of the room in which you are going to take a nap should be comfortable, and you would greatly benefit if there are no bright lights around you. The best temperature to take a nap is around 18-22 degrees Celsius.
The perfect sleep duration varies from person to person. But, as we learned, the ideal afternoon nap during your work days should not exceed 20 minutes and the deeper naps around noon should be reserved for your weekends.